(a)
(b)
Figure 3: (a) Surface charge, expressed as zeta potential (ZP), and (b) effective diameter () of “scraped” coatings from chewing gums A–E and FG-ref powder in different fluids: ultrapure water (H2O), artificial saliva (AS), phosphate buffered saline solution (PBS), and Dulbecco’s Modified Eagle Medium for cell cultures (diluted: DMEM 1 : 100; concentrated: DMEM 1 : 1).